<template>
    <div class="app-container">
  
      <!-- 添加章节按钮 -->
      <div>
        <el-button type="primary" @click="addChapter()">添加章节</el-button>
      </div>
  
      <!-- 章节列表 -->
      <ul class="chapterList">
        <li
          v-for="chapter in chapterList"
          :key="chapter.id">
          <p>
            {{ chapter.title }}
            <span class="acts">
              <el-button type="text" @click="addVideo(chapter.id)">添加课时</el-button>
              <el-button type="text" @click="editChapter(chapter.id)">编辑</el-button>
              <el-button type="text" @click="removeChapterById(chapter.id)">删除</el-button>
            </span>
          </p>
          <!-- 视频 -->
          <ul class="chapterList videoList">
            <li
              v-for="video in chapter.children"
              :key="video.id">
              <p>
                {{ video.title }}
                <el-tag v-if="!video.videoSourceId" size="mini" type="danger">
                  {{ '尚未上传视频' }}
                </el-tag>
                <span class="acts">
                  <el-tag v-if="video.isFree" size="mini" type="success">{{ '免费观看' }}</el-tag>
                  <el-button type="text" @click="editVideo(chapter.id, video.id)">编辑</el-button>
                  <el-button type="text" @click="removeVideoById(video.id)">删除</el-button>
                </span>
              </p>
            </li>
          </ul>
        </li>
      </ul>
      <!-- 章节表单对话框 -->
      <chapter-form ref="chapterForm" />
      <!-- 课时表单对话框 -->
      <video-form ref="videoForm" />
      <div style="text-align:center">
        <el-button type="primary" @click="prev()">上一步</el-button>
        <el-button type="primary" @click="next()">下一步</el-button>
      </div>
    </div>
  </template>
  <script>
  import chapterApi from '@/api/vod/chapter'
  import videoApi from '@/api/vod/video'
  
  // 引入组件
  import ChapterForm from '@/views/vod/course/components/Chapter/Form'
  import VideoForm from '@/views/vod/course/components/Video/Form'
  
  export default {
    // 注册组件
    components: { ChapterForm, VideoForm },
    data() {
      return {
        chapterList: [] // 章节嵌套列表
      }
    },
    created() {
      this.fetchNodeList()
    },
    methods: {
      // 获取章节小节数据
      fetchNodeList() {
        chapterApi.getNestedTreeList(this.$parent.courseId).then(response => {
          this.chapterList = response.data
        })
      },
      //删除章节
      removeChapterById(chapterId) {
        this.$confirm('此操作将永久删除该章节，是否继续?', '提示', {
          confirmButtonText: '确定',
          cancelButtonText: '取消',
          type: 'warning'
        }).then(() => {
          return chapterApi.removeById(chapterId)
        }).then(response => {
          this.fetchNodeList()
          this.$message.success(response.message)
        }).catch((response) => {
          if (response === 'cancel') {
            this.$message.info('取消删除')
          }
        })
      },
      // 添加章节
      addChapter() {
        this.$refs.chapterForm.open()
      },
      // 编辑章节
      editChapter(chapterId) {
        this.$refs.chapterForm.open(chapterId)
      },
      // 添加课时
      addVideo(chapterId) {
        this.$refs.videoForm.open(chapterId)
      },
      // 编辑课时
      editVideo(chapterId, videoId) {
        this.$refs.videoForm.open(chapterId, videoId)
      },
      // 删除课时
      removeVideoById(videoId) {
        this.$confirm('此操作将永久删除该课时, 是否继续?', '提示', {
          confirmButtonText: '确定',
          cancelButtonText: '取消',
          type: 'warning'
        }).then(() => {
          return videoApi.removeById(videoId)
        }).then(response => {
          this.fetchNodeList()
          this.$message.success(response.message)
        }).catch((response) => {
          if (response === 'cancel') {
            this.$message.info('取消删除')
          }
        })
      },
      // 上一步
      prev() {
        this.$parent.active = 0
      },
      // 下一步
      next() {
        this.$parent.active = 2
      }
    }
  }
  </script>
  <style scoped>
  .chapterList{
      position: relative;
      list-style: none;
      margin: 0;
      padding: 0;
  }
  .chapterList li{
    position: relative;
  }
  .chapterList p{
    float: left;
    font-size: 20px;
    margin: 10px 0;
    padding: 10px;
    height: 70px;
    line-height: 50px;
    width: 100%;
    border: 1px solid #DDD;
  }
  .chapterList .acts {
      float: right;
      font-size: 14px;
  }
  
  .videoList{
    padding-left: 50px;
  }
  .videoList p{
    float: left;
    font-size: 14px;
    margin: 10px 0;
    padding: 10px;
    height: 50px;
    line-height: 30px;
    width: 100%;
    border: 1px dashed #DDD;
  }
  </style>